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GhostRam6

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Feb 26, 2019
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Location
New Jersey
Ram Year
2008
Engine
5.7
I have a 2008 Ram 1500 5.7 Big Horn edition. My TPM, check engine, abs, parking brake, check gauges, and tire pressure warning lights all come on at the same time and the speedometer and the tack drop down to zero. Square boxes also appear around all of the gear indicators above the mileage. The lights blink and the dash bell sounds non stop I can't even drive the drive the truck. I replaced the rear abs sensor on the differential and both the input and output speed sensors on the transmission already. Abs module and PCM are also clean and free of any moisture or corrosion. All of the sensors have been pulled and check for corrosion at the harness. Does anyone know what could be causing this? Thanks
 

JSMITH8505

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Location
BIRMINGHAM, AL
Ram Year
2018
Engine
6.7 CUMMINS
Sounds electrical. Like a short of some kind.


I've seen this happen on another car when the battery was totally discharged. All the lights (ABS, Traction Control, TPMS, etc) came on and didnt go off until the battery reached a certain charge point.
So, my guess would be an electrical contact of some kind if your battery hasn't been dead lately.

Here's my list in the order to check from easy to access to harder:
1. Battery connections. There may be just enough of a gap to spark or short or enough corrosion to foul the connection up. Disconnect the battery. Clean the terminals with a bit of steel wool or SOS pad, even if they look good.

1A- Battery Output. Have it load tested at Autozone or any other auto parts store that does it.
1B- Alternator output. While you're there, go ahead and get the alternator load tested. This could find a weak alternator or Or a bad voltage regulator.

2. Ground connection on the engine block itself. A loose ground, or broken ground wire can send a feedback through the system that acts like a short.

3. Check the tiny (although insulated) wires that stick out of the wiring harnesses and plugs. We've all seen them. The wiring harness wraps cover all but the last 1/4 inch of wire. Every now and then one or two rub or get exposed and short. (Time consuming, but it's fairly easy to access).

4. Starter motor- Check for wiring connections that may be frayed. It's easy enough to look at from underneath or topside if you're nimble enough.

5. Ignition switch. The contact points could be corroded or loose just enough to short or not have a constant "good" connection. You have a physical Turn Key? Jiggle it a bit to see if that clears it up. Push Button start. Pull the button housing off carefully and check for the connection points.

6. Instrument cluster- every now and then a plug may vibrate loose. It's rare but it happens.

7. Then you'll be getting into checking relays in the fuse box. I wont go into that here, because it's not feasible to walk through, but check for loose relays first, pull one and reinsert it, ONE at a time, Key off, Engine off. and check the connection to see if they've vibrated loose.

8. Transmission Module.

Good Luck

EDIT: --------------

Does anyone know if there's something with the fuel system that triggers a no-start fault code like this? Maybe water in the fuel filter?
The more I think about this, the more I think it's gone into limp mode to try to protect itself from further damage.
I'm wondering if the transmission has a fail-safe that kicks on.

It sounds like it, but I can't figure it out.
 
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